From: Henry Spencer <henry@zoo.toronto.edu>
Newsgroups: sci.space.tech,sci.space.policy
Subject: Re: Minimum Mars crew (Was: International Space Station)
Date: Sun, 9 Jun 1996 23:30:51 GMT
In article <DsJ39G.5qz@unx.sas.com> sasbck@unx.sas.com (Brenda Kalt) writes:
>Assuming 9 months out, 9 months back, and 12 months on the surface
>(reasonable?), what is the minimum recommended crew size?
>
> 1=no, a second person could rescue the first (and cold-heartedly,
> if we've spent that much money, we need a backup of the human
> component)
> 2=? Would they kill each other?
> 3=???
Bob Zubrin recently made an excellent case that the minimum crew size for
an small "pathfinder" Mars expedition is four. There are two specialties
which are absolutely vital: flight engineer (who keeps the hardware
going, making it possible to complete the mission) and surface scientist
(who does the in-depth hands-on investigation that is the only convincing
justification for a manned mission). Both functions are sufficiently
involved to be the primary role of a specialist, and both are sufficiently
vital to demand twofold redundancy. So two engineers and two scientists.
No other function is important enough to justify adding an entire person,
and the resources to support that person, to a small crew.
--
If we feared danger, mankind would never | Henry Spencer
go to space. --Ellison S. Onizuka | henry@zoo.toronto.edu

From: Henry Spencer <henry@zoo.toronto.edu>
Newsgroups: sci.space.tech,sci.space.policy
Subject: Re: Minimum Mars crew
Date: Sat, 15 Jun 1996 16:38:23 GMT
> Well, this is in part my professional bias showing but I would've thought
> the essential non-overlapping "on-site" skills would be:
There are a lot of *skills* you need for such an expedition. The question
is, which ones are so crucial that you need full-time professionals,
rather than cross-trained amateurs? Zubrin's argument is that flight
engineer and field scientist are the two which are so important that you
need people who've built their careers around them. (Oh, the place where
this was published is the Zubrin&Weaver paper in the July 1995 JBIS -- the
part about crew selection sounds like pure Zubrin, so I tentatively
attribute it to him.)
> 2)engineer/handyperson
By far the likeliest cause of mission failure is equipment failure. For a
flight engineer, you want someone who not only knows the equipment, but
knows it forwards and backwards, spends a good part of his time watching
it, can spot trouble before it starts, and can fix things even when he
hasn't got quite the right parts. This is not a small or simple job, and
it's not something that can be picked up as a secondary specialty. It's
not something you can do without, either, so there'd better be two.
> 1)geologist/geochemist
> 4)physician/biologist
Field scientist too is pretty obvious. Despite considerable efforts made
at training the later Apollo crews, it's abundantly clear that sending a
professional geologist on Apollo 17 made a real difference. Again, the
mission is basically a failure without a field scientist (a realistic Mars
expedition involves a long stay, not a "flags and footprints" visit), so
there had better be two of them. Preferably they should have slightly
different specialties. One should be a geologist. Sending a biologist to
a planet that is *probably* now lifeless is unlikely to be worthwhile.
Zubrin's suggestion is a geochemist with a biological slant.
> 3)pilot/astronaut
What does "astronaut" mean? What does an "astronaut" do? If he's not a
flight engineer, he's a pilot. As for pilots... The only time when such
an expedition might need a pilot is for about ten seconds during Mars
touchdown. And even then, it doesn't really need a *pilot*, in the sense
of a stick-and-rudder jockey. Even Apollo-vintage computers were quite
capable of guiding a lander to a gentle touchdown. The thing they couldn't
do, and still can't, is pick a good landing spot. Telling the computer
where to land does not take a pilot; it does take some training, and some
equipment, but you don't need a professional pilot for it.
Certainly you don't need a pilot badly enough to reserve a seat for him.
Apollo demonstrated that a geologist can be trained to be a pilot, and
even more significant, it demonstrated that a flight engineer can make a
perfectly adequate pilot: Neil Armstrong's forte was engineering, not
stick-and-rudder work.
(Zubrin also notes that a crew of four doesn't need a full-time manager,
i.e. a seat labelled "captain". Somebody needs to be in charge, but
that won't be his primary job.)
> 4)physician/biologist
See above for the biologist part. As for a physician, again, a crew of
four doesn't really have a need for one. They need basic medical training,
probably one man with paramedic training, certainly a good stock of medical
equipment, information, and supplies, and high-grade help on call back home.
But a seat labelled "doctor" is excessive. Amundsen didn't take a doctor to
the South Pole.
--
If we feared danger, mankind would never | Henry Spencer
go to space. --Ellison S. Onizuka | henry@zoo.toronto.edu

Newsgroups: sci.space.shuttle
From: henry@spsystems.net (Henry Spencer)
Subject: Re: What specialties would astronauts on a Mars mission need?
Date: Wed, 31 May 2000 16:38:27 GMT
In article <20000531085221.11526.00001130@ng-fl1.aol.com>,
Andy <aseed@aol.comxnospamx> wrote:
><< Bob Zubrin has made a good case that the minimum crew is four...
>
>I would submit that a you're setting yourself up for trouble with a crew of
>four. You don't have enough variety in terms of personalities (to keep things
>interesting on the trip), and you only have enough bodies to run single-shift
>explorations on the surface.
The psychological angle is greatly exaggerated. Amundsen and Scott each
took five men (including themselves) to the South Pole -- a trip that
involved far more isolation and boredom than any Mars expedition would.
As for single-shift exploration, that's a tradeoff. Having twice as many
would be better in many ways, but it also means making everything twice as
large. Note, Zubrin didn't say this was the *optimum* crew, he said it
was the *minimum* crew... and he accompanied that with the argument that a
small expedition which gets funded is better than a big one which doesn't.
The *optimum* crew for a Mars expedition, if you don't consider cost, is
probably a lot closer to von Braun's 70.
>>...It *does* need top-notch experts on fixing broken equipment
>>in the field with inadequate facilities, so the crew makes it
>>home; that's the flight engineers.
>
>The nice thing about the current crop of astronauts is that folks generally
>(except pilots) aren't "specialists" in any particular "flight" field.
This is not necessarily a nice thing, or even a good thing. In fact, I
would argue that it's a serious mistake, the result of JSC politics rather
than rational planning. Deke Slayton, who can claim some small background
in the matter, thought that shuttle astronauts *should* specialize.
>Simply put, pilots and doctors are generally equally adept at equipment
>maintenance and repair.
An *expert* flight engineer is much better than either. Zubrin's point
was that for two jobs -- equipment maintenance and surface science -- a
Mars expedition needs *the best possible performance*, not just adequate
competence. Anyone can be trained to swap boxes, but what is wanted for a
small expedition, far from home, with limited spare parts, is someone who
"can sniff out problems before they occur and fix anything that can be
fixed". That's a much higher level of expertise than a box-swapper --
it's a full-blown professional specialty, not something you can add on.
An example, modified from something my old boss mentioned sometimes:
anybody can plug in a new transformer when the old one goes bad, but if
you don't *have* a spare, how many of today's electronics technicians
could rewind the bad one? (He was trained as a U-boat radio officer --
hmm, possibly the closest Earthly counterpart yet to a Mars-expedition
flight engineer! -- and he could and did rewind transformers when
necessary.) It's a skill, something that requires training and practice
if you want to be able to do it right when your life depends on it.
> In fact, IMHO, given the probabilities, you'd be an idiot NOT to have a
>physician on board.
Realistically, equipment failure is a lot more likely to endanger the
entire mission than illness. Expertise should be concentrated on the
crucial problems, not the secondary ones. Amundsen didn't take a doctor
to the South Pole; he did take four (!) trained navigators.
>All of the physicians
>I know in the corps (current or former) are perfectly capable flight engineers.
I'm sure they're all competent box-swappers, but how many of them can use
a soldering iron and an oscilloscope, or weld and re-balance a broken fan
blade, not to mention rewinding transformers? A Mars expedition is a very
different story from a one-week shuttle flight; ORUs won't cover it all.
If you want an example of *why* ORUs won't cover it all, consider the
spacesuits. Harrison Schmitt's estimate of the useful working life of an
Apollo spacesuit on the lunar surface was about a week, and that assumed
decent facilities for cleaning and minor repairs, and a supply of
replacement expendable items like overgloves. That just won't do for a
Mars expedition. Unless miracles can be accomplished in suit design,
somebody will have to be competent to do serious repairs (not just
swapping subassemblies, you can't *carry* that many) on the suits and
their backpacks.
>The other nice thing about physicians is they can serve, without much
>additional training, as planetary biologists.
I think the planetary biologists would have something to say about this,
and it wouldn't be complimentary. Again, field science is the key goal,
not a secondary issue, and you want to concentrate expertise on the
crucial problems. It would be nice to have a planetary biologist who also
has an M.D., but the "planetary biologist" part is the most important one.
Also, if you can send only a few scientists to Mars, and you want one with
a focus on possible life there, almost certainly you want something like a
paleobotanist, *not* a general biologist (or a doctor pretending to be
one). How many doctors know what microfossils look like?
>Why send a biologist along when
>it may turn out that their skills are completely unneeded?
You're the one suggesting it, not me... My reading is that in a minimal
crew, it should be a secondary specialty at most. With a slightly larger
crew, add the paleobotanist. In a 70-man crew, it might make sense to
have a biologist.
--
Microsoft shouldn't be broken up. | Henry Spencer henry@spsystems.net
It should be shut down. -- Phil Agre | (aka henry@zoo.toronto.edu)

Newsgroups: sci.space.shuttle
From: henry@spsystems.net (Henry Spencer)
Subject: Re: What specialties would astronauts on a Mars mission need?
Date: Wed, 31 May 2000 23:51:07 GMT
In article <39358A74.3949A99@videotron.ca>,
JF Mezei <jfmezei.spamnot@videotron.ca> wrote:
>If the first mission is just to prove the concept works and that humans are
>capable of making the trip and back, shouldn't the crew be focused on the
>travel aspects as opposed to biology of Mars?
Ideally, yes... but in practice, the orbital dynamics of getting there are
likely to dictate infrequent trips with long surface stays. That greatly
increases the incentive to get major surface-science work done each time,
including the first time.
--
Microsoft shouldn't be broken up. | Henry Spencer henry@spsystems.net
It should be shut down. -- Phil Agre | (aka henry@zoo.toronto.edu)

Newsgroups: sci.space.shuttle
From: henry@spsystems.net (Henry Spencer)
Subject: Re: What specialties would astronauts on a Mars mission need?
Date: Wed, 31 May 2000 23:38:59 GMT
In article <h6fZ4.1032$xJ2.19625@news.itd.umich.edu>,
<cmhall@umich.edu> wrote:
>Just a note. Amundsen did not take a doctor to the pole, but Scott did
>(Wilson). Not that this proves anything about doctors ;-)
Especially since nowhere in the records of Scott's expedition will you
find relevant medical terms :-) like "dehydration", "malnutrition", and
"scurvy"... even though all those conditions almost certainly were
present.
--
Microsoft shouldn't be broken up. | Henry Spencer henry@spsystems.net
It should be shut down. -- Phil Agre | (aka henry@zoo.toronto.edu)

Newsgroups: sci.space.shuttle
From: henry@spsystems.net (Henry Spencer)
Subject: Re: What specialties would astronauts on a Mars mission need?
Date: Thu, 1 Jun 2000 16:35:38 GMT
In article <8h57nq$4f8$1@news.netvision.net.il>,
Bruce <bater@netvision.net.il> wrote:
>> The psychological angle is greatly exaggerated. Amundsen and Scott each
>> took five men (including themselves) to the South Pole -- a trip that
>> involved far more isolation and boredom than any Mars expedition would.
>
>Interesting analogy Henry, but not one that I would use :)
>Scott never returned from the South Pole, he died there along with his crew
True, but that just says you need somebody competent in charge, unlike
Scott. Amundsen and all his men made it back unhurt and healthy.
To give some flavor of the contrast here... One of the little hassles of
an overland trip to the South Pole is the climb up a glacier -- crevasses
and all -- to the Antarctic Plateau, going from sea level to circa
10,000ft. On the way back, of course, you have to go back down. Quite by
chance, both the Scott party and the Amundsen party got a day of clear
sunny weather early in the descent on their return trips. They reacted
very differently.
Scott's party was starving, dehydrated, exhausted, frostbitten, hurrying
desperately against short supplies and rapidly deteriorating weather, and
debilitated mentally and physically by both B-vitamin deficiency and
scurvy. When Scott got clear weather during the descent, he stopped and
gathered rock samples. The load hauled on his sleds thereafter included
100 pounds of rocks. (It sounds incredible, but it's well documented.)
Amundsen's party was well fed, well watered, well rested, warm, well ahead
of schedule, and in good shape. When Amundsen got clear weather during
the descent, he discarded his planned schedule and ran for the bottom at
top speed, trying to finish the treacherous descent while the good
visibility lasted and he could see obstacles ahead. He reached the bottom
just before the weather closed in again.
--
Microsoft shouldn't be broken up. | Henry Spencer henry@spsystems.net
It should be shut down. -- Phil Agre | (aka henry@zoo.toronto.edu)